Single trigger sequential firing mechanism



Aug. 2, 1960 c. F. L AAGr-:R

SINGLE TRIGGER sEQuEN'rIAL FIRING MECHANISM Filed Jan. 23, 1958 III Il;/l/lfllillillll fihi.

FIG.2.

1N V EN TOR. CRESTON E LAAGER 2,947,220 l"vitaliteitAug-v 251960 SINGLETRIGGER SEQUENTIAL FIRING MECHANISM Creston F. Langer, Beverly, NJ.,assgnor to the United States of America as represented by the Secretaryf the Army Filed Jan. 23, 1958, Ser. No. 710,825

1 Claim. (Cl. 89-1) (Granted under Title 35, U.S. Code (1952), sec. 266)The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment of anyroyalty thereon.

This invention relates to trigger mechanisms such as are adapted to fireexplosive charges utilixed in the operation of aircraft escape systems.More particularly, it relates to an improved mechanism which is operatedby one motion of a single trigger to determine the charge to be firedand to cock and release the tiring pin of the selected charge.

As hereinafter explained, this arrangement has the very importantadvantage over those heretofore proposed that it positively insures thatthe explosive charges are fired in the proper order and does away withcertain mechanical devices, such as cables, pulleys and rods, which havenot been altogether reliable in operation.

Currently used in high speed airplanes are escape devices which jettisonthe canopy and catapult the pilot away from a disabled craft. Thesedevices depend for their motivation upon the energy released by anexploding cartridge. The device jettisoning the canopy is known as theremover. That ejecting the pilot is called a catapult. Each containpowder charges and each is tired by gas pressure generated by a deviceknown as an initiator. The initiator generates gas when a cartridgecontained within it is red by actuating its tiring pin manually.

Two separate initiators are customarily used and each is firedseparately by the pilot. Present installations utilize cables, pulleysand various other mechanical devices. Some are diicult to operate undersome circumstances. Others have failed and resulted in loss of lifebecause of the nature of the operating rigs. It has been possible, forexample, to re the catapult before the remover with the result thatpersonnel was projected through the canopy. All these difficulties areavoided by the present invention which is of relatively simpleconstruction and positively insures that the initiators are tired in theproper order.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope is indicated by the appended claim.

Referring to the drawings:

Fig. 1 is a sectional view of a preferred form of the invention, and

Fig. 2 is a section taken on the line 2-2 of Fig. l.

The mechanism of these figures includes a trigger which has a removablecover 9 and is an integral part of a member 11. This member is slidablealong a rod 12, is biased to its illustrated position by a spring 13,and

2. has pivoted to it a pawl 14 which is biased to its illustratedposition by a spring 15. The pawl 14 is arranged to cooperate with afour lobed cam i16 which is fixed to a gear 17. This gear is revolveddegrees by one stroke of the trigger 10. l

The gear 17 bears a pin 17 which is arranged to en gage one end of asear 18. This sear rides on a rocker 19 which permits it to angle awayfrom engagement with the pin 17' when it has been moved a predetermineddistance by counterclockwise rotation of the gear 17 It should beunderstood that this action is facilitated by the arrangement of thelower end of the scar 18, which at one side is sloped and connected to aspring 21 and at the other side is bifurcated to straddle the firing pin20 and offset to engage a notch near the top of the firing pin. Thus themember 19 maintains the sear 18 in engagement with the ring pin 20during the initial movement of the scar. When the lower end of themember 19 engages the offset part at the lower part of the sear however,the lower end of the sear is released to the point where it is moved tothe left by the spring 21 and is disengaged from the firing pin 20 whichis thereupon activated by the spring 22.

This one stroke of the trigger 10 functions through the pawl 14, the cam16, the gear 17, the sear 18, the rocker 19, and the spring 21 tocompress and release a spring 22 which provides the energy for firing aprimer 23. As previously indicated, the primer 23 is a part of aninitiator 24 which is connected through a exible tube to the tiring pinof the canopy remover and generates a gas for activating this firingpin. This action leaves the sear 18 out of engagement with the gear 17so that this gear is now rotatable independently of the sear.

Meshing with the gear 17 is a second gear 25 bearing a pin 26 adapted toengage a sear 27 of a mechanism by which an initiator 28 in the samemanner as that described in connection with the firing of the initiator24.

The initiators 24 and 28 are of a well known type wherein a firing pinpiston is surrounded by a seal ring 29. Each of them is adapted to firea cartridge 30 for generating a gas under pressure which is appliedthrough a port 31 and a tube (not shown) to the tiring pin of acartridge which activates the canopy remover or the catapult.

Obviously, more than two initiators can be similarly fired by theaddition of more gears and pins. The described mechanism has theadditional advantage that it permits a second firing in the case of amislire of the catapult, since a fourth pull of the trigger again bringsthe pin 26 into engagement with the sear 27 I claim:

In an apparatus for generating a gas pressure and for applying said gaspressure to a device to be operated, the combination of a support, apair of initiators fixed to one end of said support with theirlongitudinal axes parallel to one another, each of said initiatorshaving a tiring pin, a spring biasing said ring pin to its uncookedposition, a gear, a sear extending between and releasably coupled tosaid gear and said ring pin, said sear having a surface which is flatadjacent said gear and is offset adjacent said firing pin, a rocker armpivoted to said support and having relatively long and short arms and aspring tensioned to maintain said arms in engagement gear and from saidfiring pin when said relatively shortnu arm engages the offset part ofsaid surface, the gears of said initiators being in mesh with oneanother, actuating means including a pawl biased into engagement withone of said gears, said actuating means being mounted at the other endof said support and being movable transversely of said longitudinal axesfor alternately ring said initiators, and means for returning saidactuating Y' leerhe-ncesl Cited in the le of this patent means to itsoriginal positionafter each of its movements. 10 2,902,788

ITD STATES PATENTS Granger July 28, 1891 Kilgore July 27, 1909 StanleySept. 21, 1954 Polny Feb. 15, 1955 Martin Feb. 28, 1956 Foster Jan. 21,1958 Laager Sept. 8, 1959

